Finishes

Finishes, either internal or external, are methods of modifying fibres. Internal finishes are within the fiber structure; external finishes are applied to the surface of a fibre, yarn or fabric. External finishes may alter the appearance, feel and/or performance of a fabric. Some of the more common finishes used on carpet include:

* Antistatic finish. Different agents are necessary for different fibres. Some are surface applications that are not durable and must be replaced after cleaning the carpet. Some carpet manufacturers incorporate metallic fibres into the yarn, which help some in controlling static, but researchers are still looking for a durable antistatic agent. Besides the electrical shock hazard, static causes carpet to attract soil. Static builds up more in dry, cold climates, so is more prevalent during Nebraska winters. Avoid spraying anti-static finishes that are not specifically approved by the manufacturer. To do so may void the warranty. Using an anti-static spray on some types of carpet can cause the carpet to soil faster.

* Flame retardant -- Flame-retardant finishes reduce flaming, charring and/or afterglow. Flammability labeling is not required on residential carpeting, but all carpet must comply with Department of Commerce standards (FF1-70 or FF2-70) designed to protect consumers from small ignition fire sources (matches, cigars, cigarettes, stove or fireplace embers). These do not ensure that a carpet is flameproof.

The toxic smoke fumes from burning carpet can be more hazardous than the flames. For this reason, look at the manufacturer's information and compare the flame spread and smoke emission factors. The lower these number the safer the carpet. This should be of special interest if you have a wood or coal stove.

* Mothproofing. Protein fibres, especially wool, are highly susceptible to moth damage. Most wool and wool-blend carpets today have been permanently mothproofed and are so labeled. Carpets containing wool that are not permanently mothproofed should be kept clean. Researchers continuously are looking for new ways of making wool mothproof, including finding a substance sheep might eat to make their wool naturally mothproof. Synthetics do not require mothproofing.

* Soil resists and stain resist finishes. Seventy to ninety percent of carpets sold are treated with a soil resistant finish. A soil resistant finish allows the carpet to remain clean up to three to four times longer than untreated carpets according to the Carpet and Rug Institute. Soil resistance protects the carpet by keeping dirt from sticking so tightly to the fiber, and provides some protection against stains. Loosely held dirt can be removed more easily from the treated carpet with regular vacuuming. Soil resistant finishes may be fluorochemical or silicone (the majority is treated with fluorochemicals). Fluorochemical treatments protect against both water- and oil-borne soils and resists wetting by oily and watery liquids. Silicone treatments protect against water-borne soils and watery liquids only.

Factory-applied finishes can be applied at different stages during the manufacturing of carpet. The chemical finish is applied to individual fibres before they are prepared for carpeting, during the dyeing process, or after a carpet is produced.

The stain resist finishes used are complex mixtures - typically blends of phenol resins and other copolymers (e.g., acrylics). They are usually applied after the carpet has been dyed to resist dyes found in other products such as spilled foods.